Iron ore tailings dry stacking in Pau Branco mine, Brazil

The mining industry has seen several significant dam failures in recent years. Dam failures are associated with errors in design, implementation, operation, and monitoring (Azam, 2014, [2]). Dewatered stockpiling (dry stacking) is a safer alternative to tailings dams (Rico et al., 2008, [3]) for tailings disposal; however, this method has not yet been used in iron ore mines in Brazil, where geotechnical conditions and abundance of water are favorable for the use of tailings dams. This paper describes the results of the study that supported the implementation of an innovative dewatering plant for iron ore tailings in Pau Branco mine, Quadrilatero Ferrifero, Brazil, contributing to improve its sustainability (Gomes et al., 2015, [6]). Magnetic concentration rejects (>45 μm) were feasibly dewatered through high-frequency screenings, and slimes (<45 μm) were effectively filtered in a horizontal filter press, enabling dry stacking of tailings. A comparison with the current tailings dam structure is presented, demonstrating that Capital Expenditure (CAPEX) for the solution proposed here is significantly lower.